Boxmoor
https://mailchi.mp/c0c783fd1b7a/x37u3xe2mf This site is really useful, keeping up to date with classes/group play and events. Check which community centre is near you, go there and ask the team of any questions you have about joining classes. They are really friendly and supportive team.
Sign up with the family centre. They have lots of free classes in the area. The Friday rhyme time one is good x
What area of Dacorum are you from?